High-energy breakfast with low-energy dinner decreases overall daily hyperglycaemia in type 2 diabetic patients: a randomised clinical trial

Aims/hypothesis: High-energy breakfast and reduced-energy dinner (Bdiet) significantly reduces postprandial glycaemia in obese non-diabetic individuals. Our objective was to test whether this meal schedule reduces postprandial hyperglycaemia (PPHG) in patients with type 2 diabetes by enhancing incretin and insulin levels when compared with high-energy dinner and reduced-energy breakfast (Ddiet). Methods: In a randomised, open label, crossover design performed in a clinic setting, 18 individuals (aged 30–70 years with BMI 22–35 kg/m²) with type 2 diabetes (<10 years duration) treated with metformin and/or diet were given either Bdiet or Ddiet for 7 days. Participants were randomised by a person not involved in the study using a coin flip. Postprandial levels of plasma glucose, insulin, C-peptide and intact and total glucagon-like peptide-1 (iGLP-1 and tGLP-1) were assessed. The Bdiet included 2,946 kJ breakfast, 2,523 kJ lunch and 858 kJ dinner. The Ddiet comprised 858 kJ breakfast, 2,523 kJ lunch and 2,946 kJ dinner. Results: Twenty-two individuals were randomised and 18 analysed. The AUC for glucose (AUC_glucose) throughout the day was 20% lower, whereas AUC_insulin, AUC_C-peptide and AUC_tGLP-1 were 20% higher for the Bdiet than the Ddiet. Glucose AUC_0–180min and its peak were both lower by 24%, whereas insulin AUC_0–180min was 11% higher after the Bdiet than the Ddiet. This was accompanied by 30% higher tGLP-1 and 16% higher iGLP-1 levels. Despite the diets being isoenergetic, lunch resulted in lower glucose (by 21–25%) and higher insulin (by 23%) with the Bdiet vs Ddiet. Conclusions/interpretation: High energy intake at breakfast is associated with significant reduction in overall PPHG in diabetic patients over the entire day. This dietary adjustment may have a therapeutic advantage for the achievement of optimal metabolic control and may have the potential for being preventive for cardiovascular and other complications of type 2 diabetes. Trial registration ClinicalTrials.gov NCT01977833 Funding No specific funding was received for the study.